1. Field of the Invention
The present invention relates to a camera having a camera body with a back door provided at the back of the camera body and a pressure plate disposed in the camera body and, more particularly, to a pressure plate mounting structure for mounting such pressure plate to such back door.
2. Description of the Related Art
Most of 35 mm cameras using 35 mm film cassettes and many of roll-film cameras using, for example, 120 or 220 roll-films have a camera body with a back door provided at the back of the camera body for closing and opening a film cavity defined in the camera body. Such cameras also have a pressure plate disposed in the camera body for establishing required flatness of the portion of a filmstrip that is then located in the exposure area. Typically, the pressure plate is mounted to the inner side of the back door by means of one or more leaf springs, which serve to urge the pressure plate in the forward direction of the camera so as to press the front surface of the pressure plate against the back surface of the portion of the filmstrip in the exposure area.
There has been known a traditional mounting structure for mounting a pressure plate to a back door through one or more leaf springs, in which the leaf springs have one end secured to the back door by means of miniature setscrews and the other end to the pressure plate also by means of miniature setscrews. This mounting structure uses many miniature setscrews in total. It is difficult to automate such an assembly operation that requires miniature setscrews to be set and tightened, while a manual assembly operation handling miniature setscrews is time-consuming. This has been one of major difficulties in reducing assembly costs of cameras.
More recently, various pressure plate mounting structures have been developed in order to reduce required miniature setscrews used for mounting a pressure plate to a back door of a camera, including Japanese patent publication No. Hei-2-36827. This patent publication discloses a mounting structure for mounting a pressure plate to a back door of a camera, in which only one setscrew is used to secure a pressure plate support member onto the back door.
However, in any of prior art pressure plate mounting structures designed in an attempt to reduce setscrews required, the reduction of setscrews has been achieved only by using a certain additional support member and/or other fixtures such as pins and clips. The use of such additional parts has made it difficult to achieve the final purpose, i.e., reduction in assembly costs of cameras.